Inhalers are commonly used to deliver a wide range of medicaments. The inhaler holds a canister of medicament which is actuatable, for example by compression, to deliver a dose of medicament. Some known inhalers are provided with an actuation mechanism for actuating the canister. The mechanism may be breath-actuated i.e. arranged to actuate the canister in response to inhalation at the mouth piece. Typically a breath-actuated inhaler includes a loading mechanism for loading a resilient loading element with an actuation force for compression of the canister. A triggering mechanism may be provided to hold the resilient loading element against compression of the canister, the triggering mechanism releasing the resilient loading element upon inhalation.
Important considerations for an actuation mechanism are reliability and simplicity. Reliability is important to ensure that the medicament is correctly delivered on every use, especially when the medicament is required by the user in an emergency. A simple structure is required firstly to assist in ensuring that the actuation mechanism operates reliably and secondly to simplify manufacture, thereby reducing manufacturing costs.
A problem often encountered, especially by elderly, young and infirm users, is that it is difficult to generate enough force to load the resilient loading element provided to bias actuation of the canister. The energy with which the resilient loading element is loaded must be sufficient to actuate the canister which can create difficulties for some users. The first aspect of the present invention is intended to assist in loading of the mechanism.